Question 27Navigation Problems

The correct answer is A) 81 RPM. To calculate the required RPM, we can use the formula: RPM = (Speed in knots x 1.6889) / (Propeller Pitch in feet). Given: - Speed = 18.7 knots - Propeller Pitch = 24.05 feet (24'03" converted to feet) - Positive slip = 3% Accounting for the positive slip, the actual speed is 18.7 / (1 - 0.03) = 19.28 knots. Plugging these values into the formula: RPM = (19.28 x 1.6889) / 24.05 = 81 RPM The other options are incorrect because they do not correctly apply the formula and account for the given propeller pitch and positive slip.